User-System Interface (USI) design is a highly iterative process involving empirical testing and evaluation. The existence of a design specification is implicit in this design process. The quality of the design specification impacts the length and cost of the design cycle. A survey was made of available USI specification tools to determine: which USI components they can specify; their relation to a finite state model of the USI; and if they are usable by the human factors engineer as a basis for an analytic analysis of a USI design to detect violations of excepted USI design guidelines. Four categories of tools were surveyed: semi-formal techniques, Backus-Naur Form grammars, programming languages, and transition networks. An engineering tradeoff analysis was performed based on four pragmatic criteria: understandability, efficiency, expressive power, and fidelity. The results of the tradeoff analysis suggest that specification tools differ in representational strength and it is best to use a set of tools for a complete specification. A behavioral study using human factors engineers was performed to validate the results of the tradeoff analysis. Human factors graduate students were trained in the use of one of three specification tools and asked to perform an analytic analysis looking for design defects. Fifteen design defects were embedded in each of the specifications. Results suggest that using two of the tools together is the most effective specification technique. In light of these results, current and future software design practices were examined to determine what role the human factors engineer can have on the design team. / Master of Science

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Engineering. / This dissertation shows that the engineering information system (EIS) is the primary integration mechanism in computer integrated manufacturing. The EIS has been defined by creating a functional as well as an information model. These models are the initial steps in the process of implementing an EIS by means of a database management system. The modelling of the EIS is defined within a work brealcdown structure for CIM acquisition which is applicable to any CIM project. The impact of the scope CIM of and the changes this requires are also defined. It is also shown that for an enterprise involved in the manufacture of complex systems it is more beneficial to introduce CIM in those areas outside the area of factory automation, The complexity of the EIS information model is such that it has not been possible to construct it manually. Automated tools should be used to create the EIS information model. / Andrew Chakane 2018

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An improved quality control model is suggested in this thesis. The improved quality control model is derived by treating the quality control problem as a process control problem. The quality control model is developed by formulating a process control model in terms of product quality parameters and control variables which affect the product quality parameters. SQC is used in the model to provide estimates about the state of the product quality variable as the product is processed by the plant. A state variable approach is used to determine the optimal control strategy. An example quality control model is formulated for a coke size-reduction process. Numerical values are assumed and sensitivity analysis results are discussed. The results show that the proposed quality control model is reasonable. Extensions to more complicated models are discussed. / M.S.